Electric controller.



M. P. HOLMES.

I ELECTRIC CONTROLLER.

APPLICATION FILED IIIIIY I1. Ism.

1,292,777. Patented Jan. 28,1919.

2 SHEETS-SHEET l.

M.. P. HOLMES..

ELECTRIC CONTROLLER.

APPLICATION FILED III/w II. 19M.

1,292,777. A Pawmd In.28,1919.

2 SHEETS-SHEET 2.

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UNITED s'rnfrns PATENT OFFICE.

MORRIS P. HOLMES, OF CLAREMONT, NEW HAMPSHIRE, ASSIGNOR T0v SULLIVAN MACHINERY COMPANY, OF CLAREMONT, NEW HAMPSHIRE, A CORPORATION OF MASSACHUSETTS.

ELECTRIC CONTROLLER.

Specification of Letters Patent.

Patented Jan. 2e, 1919.

To all whom t may concern.'

Be it known that I, MORRIS P. HOLMES, a citizen of the United States, and a resident of Claremont, New Hampshire, have invented an Improvement in Electric Controllers, of which the Vfollowing description,

in connection with the accompanying drawings, is a specification, like characters on the drawings representing like parts.

This invention yrelates to fuse plugs such for example as are employed in electrical controllers for mining and other machines.

The character of the invention may be best understood by reference to the following description of an illustrative embodiment thereof shown in the accompanying drawings, wherein:

Figure 1 is a front elevation of a portion of a controller boX equipped with a fuse plug embodying the invention;

Fig. 2 is a transverse section on an enlarged scale showing the plug locked against removal; and

Fig. 3 is a view similar to Fig. 2 showing the plug unlocked.

Referring to the drawings, 1 designates a part of a casing containing a plate 3 to which is secured a line terminal 5. On` the opposite face of said plate is a series of contacts 7 conveniently arranged in an arc of a circle. A spring pressed brush 9 is adapted to wipe over these contacts, said brush being mounted in a head 11 connected by an arm 13 with a terminal 15 in axial alinement with the line terminal 5, referred to. The arm 13 is secured to a plate 17, the latter in turn being connected to a collar 19 of a hollow shaft 21 journaled in an opening in the casing 1 andprojecting out beyond the exterior face thereof, where it receives a handle 23 fast thereon. When this handle is rocked it operates through the shaft 21 and moves the brush 9 over the contacts 7. To indicate the positions of the handle corresponding to the contacts 7 a segmental plate 25 is secured to the casing 1 and is rovided with a series of indentations 27 Fig-1). The handley 23is formed to present a boss 29 containing a spring pressed pin 31 having its inner end rounded so that when the handle is rocked the pin may automatically click over said indentations and properly locate the handle positions corresponding to the contacts.

To locate a position of the handle where it is effective to break the current the segment 25 has an additional indentation 33 deeper than the indentations 27 referred to and more fully hereinafter described.

To connect the line terminal 5 with the brush terminal 15, there is provided a fuse plug 35comprising a holder 37 of mica or other insulation material having reduced ends, on one of which is fitted and secured a cup-like bronze terminal 39 having a stud 39, and on the opposite end of which is fitted and secured a cup-like bronze terminal 41 having a longer stud 43 projecting therefrom. A fuse wire 45 of soft drawn copper or other appropriate material is stretched through the holder from one of said terminals to the other. The 'ends of the wire are adapted to project beyond the terminals, where they are set in slots in said studs and thence are wound around the same and secured thereto by nuts 47. The holder may have a lining 49 of asbestos or other suitable material. To receive and support the holder the plug is provided with a socket 51 adapted to receive the stud 43, the latter being threaded thereto. The socket in turn is received by a sleeve 53 of mica or other insulation material having a recess at one end to accommodate one of the nuts 47 A shell 55 is fitted tightly over said sleeve. At the outer end of the plug is a knob 57 of insulation material and having a reduced lportion fitting within the shell and a further reduced portion fitting within the insulation sleeve 53. This knob is bored to receive a screw 59 threaded to said socket 51 and having a head set in a counter-bore which may be filled with sealing wax. When the screw is tightened it pulls the socket 51 toward the head. The socket has an external shoulder 61 engaging an internal shoulder of the sleeve, and the latter has a shoulder 62 engaging an end of the shell 55. Consequently the tightening of the screw acts through said parts and draws and secures them tightly together with no possibility of the escape of a spark or lire therethrough.

When it is desired to replace a burnt out fuse by a new one the plug may be grasped by its head and readily pulled out of the casing. rlhen the holder is turned to unscrew the stud L13 from the socket 51, thereby rendering the nuts which secure the ends of the fuse conveniently accessible for adjustment to permit the removal and insertion of the fuses.

An important feature of the invention relates to the provision of means for preventing the withdrawal of the plug fromthe casing for any purpose excepting at times when the controller handle is in a position to prevent any current of electricity flowing through the apparatus. To accomplish this the shank of the handle is bored to receive a spring pressed latch 63 adapted to progect through a hole in the shaft 21 and'a hole in the plug 35. vWhen the plug is in this position it connects the terminals 5 and 1 5, as shown in Fig. 2. One end of the latch is tapered to coperate with a correspondingly tapered peripheral groove 67 in the spring pressed pin 31. vWhen the controlling handle is in a position with said pin 31 engaging any of the indentations 27 the cylindrical portion of the pin is in engagement with the tapered end of the latch. Then the latter is held in locking engagement with the plug. It will remain so as long as the handle is in any of its positions corresponding to the indentations 27. lf, however, the handle is rocked to a position. where its spring pressed pin enters the deeper indentation 33 referred to, the peripheral groove 67 of said pin will come into alinenient with the latch 63 and the latter will be moved by its spring into said groove and out of the plug hole 65. Then the plug is 'free to be withdrawn. lWhen the handle is in position with its pin in engagement with the deep indentation 33 the brush 9 is not in engagement with any of the contacts 7 and there is no electricity flowing through the apparatus. As a result there can be no possibility of flashing, sparking or arcing on the removal of the pluO, and danger of an explosion in the mine or other place where the machine is used is eliminated.

The plug is formed to fit the sleeve shaft accurately and the sleeve shaft is formed to fit its bearing in the casing accurately. The sleeve shaft is long and therefore has a long length of surface in engagement with the plug. The sleeve shaft flange within the casing is urged tightly against the latter by the pressure of the spring pressed brush which reacts through its arm. This is assisted by the pressure of the spring of the handle pin 31. These features prevent any possibility of the escape of fire through the casing at the point where the fuse plug is introduced therein.

l/Vithin the casing is a reversing switch G9 coperating with usual electrical connections unnecessary to be shown and described herein.

In the illustrated embodiment of the invention the fuse plug shown is employed in connection with an electrical controller for a mining machine where the contacts are arranged in a closed, contact-carrying chainber designed for considerations of safety to prevent the escape of sparks or fire into the atmosphere at the exterior of the casing, it being required, however, to locate the controller handle exterior to the casing and to have the fuse plug also exteriorly accessible. Tlie invention, however, is applicable to any case where it is required to provide a fuse plug for an electrical circuit passing through contacts located in a space which is spark-insulated from another space and where the fuse plug is required to be accessible from the last mentioned space.

Having described one illustrative embodiment of the invention without limiting the same thereto, what I claim as new and desire to secure by Letters Patent is:

1. The combination of a casing, a series of controller contacts therein., a brush in said casing movable over said contacts, a line terminal, an arm for said brush, a handle eX- terior of said casing, a sleeve connecting said brush arm and handle, a segment on said casing having indentations corresponding to said contacts and a deeper indentation, a spring pressed pin carried by said handle adapted to enter said indentation, a fuse plug fitted in said sleeve and having terminals for contact with said line and brush terminals, and a spring pressed pin controlled by said handle pin for locking said plug against removal from said sleeve eX- cepting when said handle is in a position with its spring pressed pin in said deeper indentation.

2. The combination of a casing, a series of controller contacts therein, a brush in said casing movable over said contacts, terminals within said casing, a handle exterior of said casing, means including a sleeve shaft connecting said brush and handle, means cooperating with said handle for indicating current controlling positions of said handle, means coperating with said handle for determining the position of the latter for breaking the circuit, a fuse plug in said sleeve for connecting said terminals, and means coperating with said handle for preventing removal of said plug from said sleeve `excepting when said handle is in a position to break said circuit. y

*3. The combination of a casing, contact means therein, a brush coperating with said contact means, means including a handle exterior of said casing for moving said brush relative to said contact means, a fuse plug for introduction into said casing, and locking means carried bysaid handle for preventing the removal of said fuse plug from said casing excepting when said handle is in a position to break the circuit.

4. The combination of a casing, contact means therein, a brush coperating with said contact means, means including a yrotary member having a handle exterior of said casing for moving said brush relative to said contact means, a removable fuse plugl arranged concentric with saidrotary member, and means including a movable pin for preventing the removal of said plug from said casing excepting when said handle is in a position for preventing the How of current.

5. The combination of a casing, contact means therein, a brush coperating with said contact means, means including a handle exterior of said casing for moving said brush relative to said contact means, means including a spring pressed pin carried by said handle coperating with means on said casing for indicating positions of said handle corresponding to said contact means, a fuse plug for introduction into said casing, and a spring pressed latch cooperating with said pin for preventing the removal of said fuse plug from said casing excepting when said handle is in a position to break the circuit.

6. The combination of a casing, electrical controlling means coperating therewith including a handle, a hollow shaft therefor, a fuse plug for introduction into said shaft, and means for preventing the removal of said plug from said shaft excepting when said handle is in a position for preventing the flow of current.

7. The combination of a casing, electrical controlling means including a handle, a fuse plug for introduction into said casing, a spring pressed pin carried by said handle and coperating with said casing for indieating positions of said handle, a peripheral groove in said pin, and a locking latch for said plug carried by said handle and movable into said groove to release said plug.

8. The combination of a casing, contact means therein, a rotary controller for said Contact means including a rotary member having a handle exterior of said casing, and a circuit closing means comprising a member arranged concentric with said rotary member extending into said casing, and accessible from the Vexterior thereof.

9. The combination of a casing, contact of said casing to the interior thereof, a han- "f dle on said shaft exterior of said casing, and

means carried by said handle and controlled by the position thereof for locking said fuse plug against removal.

ll. The combination of a casing, contact devices therein, a rotary shaft for operating said devices journaled in the wall of said casing, a fuse plug arranged concentric with said shaft and extending from the exterior of said casing to the interior thereof, a handle on said shaft exterior of said casing, and means controlled by the position of said handle for locking said fuse plug to said shaft.

l2. The combination of a casing, contact devices therein, a hollow rotary shaft for operating said devices j ournaled in the wall of said casing, a fuse plug extending through said shaft from the exterior of 'said casing to the interior thereof, a handle on 'said shaft exterior of said casing, .a pin extending through the wall of said shaft and engaging said fuse plug for locking said plug to said shaft, and means carried byv said handle and controlled by the position thereof for operating said pin.

13. The combination of a casing, contact devices therein, a hollow rotary shaft for operating said devices journaled in the wall of said casing, a fuse plug extending through said shaft from the exterior of said casing to the interior thereof, a handle on said shaft exterior ofsaid casing, a pin extending through the wall of said shaft and engaging said fuse plug for locking said plug to said shaft, an operating device for said pin carried by said handle, and means on the wall of said casing for controlling said operating device.

14. The combination of a casing, contact devices therein, a rotary controller for operating said devices journaled in the wall of said casing and extending to the exterior thereof, circuit closing means comprising a member arranged concentric with said rotary controller and also extending to the exterior of said casing, and means for locking said last named circuit closing means against movement to break the circuit except when said controller is in a position for prevent` ing the flow of current.

l5. The combination of a casing, contact4 members therein, a brush cooperating with said contact members, a hollow shaft by circuit except When said handle is in a pos?- which said brush is carried, said shaft being tion for preventing the flow of current. journaled in the Wall of said casing, an oper- In testimony whereof, I have signed my ating handle carried by said shaft at the eX- name to this specification7 in the presence of 5 terior of said casing, circuit closing means two subscribing Witnesses.

comprising a member arranged concentric with said shaft Within the same and acces- MORRIS P' HOLMES' sible from the exterior of said casing, and Witnesses: means for locking said last named circuit R. C. OsGooD,

10 closing means against movement to break the R. M. PADDOGK.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Wallington, D. C. 

